The importance of preserving plants and cut flowers continues to increase as consumers demand a greater selection of plants and flowers from around the world. Consumers have come to expect florists to provide a variety of non-indigenous plants, and out of season flowers, from around the world. Better plant and cut flower preservation can allow longer enjoyment of flowers by customers after jet/ocean transport, regional wholesaling, and retail display by the florist.
One requirement for preservation of most uprooted or cut plants is water. Many flowers and plant parts quickly lose turgidity and wilt without a ready supply of water at the cut stem. It is an ancient practice to increase the attractive life of the flowers by keeping cut stems in water, typically refilling and changing infested water as the flowers degrade. Provision of preservative media with certain salts and sugars in the water, to maintain an appropriate osmotic balance, has been known to forestall wilting of cut flowers. These approaches, though useful, provide only a short respite from wilting and degradation for many types of cut flowers. In addition, the presence of liquids in flower shipments has been forbidden by many airlines, due to the potential damage from spilled solutions on the aircraft and cargo.
Microbes can degrade the appearance of plants and cut flowers in storage and during transport. Systemic attacks by bacteria often originate in stem water and can cause the flowers to wilt early. Fungi can colonize the outside of the plants, making them appear rusty or moldy. A variety of methods have been used to combat microbial destruction of plants and cut flowers, such as the use of sterile technique, refrigeration, application of biocides, and the use of antibiotics.
Microbial load can be reduced through the practice of sterile technique. Sterilized fertilizer can be fed to the plants during the growth period. Plants can be grown in artificial, or sterile soil and harvested without contact by contaminated surfaces. Cut flowers can be packaged in particle controlled environments, such as within HEPA filtered rooms. Such practices can be expensive and may fail due to the large variety of microbes that normally populate plant surfaces, even with these precautions.
The application of biocides, such as ozone, ethanol, or sodium hypochlorite, can kill microbes on the surface of plants. Still, many microbes, such as spore-forming bacteria and fungi, can survive the treatment. Biocide treatments are generally harsh and can harm plant surfaces or the color of flowers.
Antibiotics can be useful in preventing microbial infestation of cut flowers. Antibiotics, and anti-fungals, in stem water can stop microbial contamination of the water. The antibiotics can diffuse systemically to protect the entire cut plant. However, even broad spectrum antibiotics do not stop all microbes. Widespread use of antibiotics can select for resistant microorganisms and should be avoided. Stem water with antibiotics may not be safe should it be consumed by children or pets.
Flower wilting can be caused by exposure to ethylene, a gaseous natural plant hormone that can be generated in the cut flowers. Ethylene levels can be reduced by supplying ventilation. For example, in U.S. Pat. No. 4,515,266 to Meyers, “Modified Atmosphere Package and Process”, produce is preserved by venting a storage container with a mixture of inert gasses. Another way to minimize the damage caused by ethylene is by application of anti-ethylene agents, such as, e.g., MCP (methylcyclopropene), which is known to inhibit ethylene production under certain conditions.
Aerobic bacteria and fungi can be inhibited by removing oxygen from the environment. For example, U.S. Pat. No. 5,564,225 to Quiding et al., “Method and Apparatus for Packaging and Preservation of Flowers and Other Botanicals”, describes how cut flowers can be preserved by packaging them in a mixture of inert gasses under a partial vacuum. However, the equipment and packaging materials involved can be expensive. In addition, factors other than aerobic microbes can still deteriorate the uprooted plants and cut flowers.
Plants can be stabilized by hermetically sealing them in a container. However, this often creates more problems than it solves, e.g., due to condensation on container walls contaminating the plant and/or build up of metabolic product gasses that can accelerate degradation of the plant.
In view of the above, a need exists for ways to ship plants and store plants in a suspended state. It would be desirable to have a shipping and storage container that preserves moisture without wetting plant surfaces. Benefits can be provided from systems and methods that provide water and preservative components to plants in storage without creating environments conducive to growth of undesirable microbes. The present invention provides these and other features that will be apparent upon review of the following.